The compositions recorded here are a product of work with computers in synthetic speech, song and vocal sounds and were created between 1972 and 1975. The music was realized on two different computer music systems and takes advantage of, and attempts to extend and explore their features. The system employed to realize speech songs was created at the Bell Telephone Laboratories for research in synthetic speech and speech communication. Since the system was not designed for musical purposes, its limitations were severe and its musical use a great (and often rewarding) challenge. The system used for In Celebration and The Story of Our Lives was designed with the expressed purpose of creating synthetic musical voices, and was therefore much better suited to the task at hand. As with any high technology project, there was extensive collaboration in the production of the works.

The works on this disk are called computer music because the sounds were created numerically in a computer before reaching magnetic tape and loudspeakers. The computer did not compose the music. However, it was only used as a sound synthesis and analysis medium. In order to hear the sounds which are represented in the computer as successions of numbers it was necessary to attach a digital-to-analogue converter to the computer. The converter transformed the succession of numbers into a fluctuating voltage which was recorded directly on to audio tape.

The technique used to create the synthetic voices is called speech synthesis-by-analysis. For this method of speech synthesis, only those words, phrases and sentences which have been spoken into the computer previously (via an analogue-to-digital converter) may be synthesized. First the digitally-recorded speech is analyzed by programs which extract the attributes (parameters) of the speech for short time segments (.01 sec.). From these parameters the speech may be recreated in a form which resembles the original recording very closely. But for musical purposes the parameters are most often altered before synthesis. It is possible, for example, to change the natural pitch contour of the speech into a melodic line or to change the speech speed without altering the natural pitch level.

The variety of musical patterns which may be created from the analytic parameters is limited only by the composer's imagination. Most of the speech sounds on the recording were created by changing the pitch and duration attributes of the original on resynthesis, but for a few, the resonances (the formants) of the speech were altered as well. The voice of the book in The Story of Our Lives was created by replacing the program which simulates the sound of the human vocal cords with one consisting of 64 sine tones glissandoing at different rates. All the textures in which more than one voice is heard were obtained by mixing the synthetic voices together digitally.